KR20220018893A - Thermal detector and multi-conductor cable - Google Patents

Abstract

The present invention provides heat detection wire and a multi-conductor cable capable of accurately detecting a temperature rise in a multi-core cable laid in a case. The heat detection wire comprises: a first conductor (211); a pair of twisted pair wires (22) twisted with a pair of heat detection wires (21) having a first insulator (212) covering the periphery of the first conductor (211). The heat detection wire (2) is made of a copper alloy in which the first conductor (211) is a non-magnetic material and has a tensile strength of 900 MPa or more.

Description

Thermal detection wire and multi-core cable {THERMAL DETECTOR AND MULTI-CONDUCTOR CABLE}

The present invention relates to a heat detection wire and a multicore cable.

In order to detect a fire, a fire detection wire is conventionally used (for example, refer patent document 1). A fire detection wire is a twisted pair of a wire for fire detection which has a conductor made of steel wire, such as a piano wire, and a low-melting-point insulator covering the periphery of the conductor. wire) and is configured to cover the twin strands with a jacket.

Conventionally, the fire detection line is arranged to follow the cable. For example, in a multi-core cable used for non-contact electric power feeding, a fire detection line is provided between the multi-core cable and a case accommodating the multi-core cable.

: Japanese Patent Laid-Open No. 58-86695

In a multicore cable laid in a case, for example, when used for non-contact electric power feeding, a large current flows through an electric wire arranged in the multicore cable. Therefore, when an excessive current flows through an electric wire for some reason, the temperature in a multicore cable rises and there exists a request|requirement to suppress that it leads to a fire.

Therefore, an object of the present invention is to provide a heat detection wire and a multi-core cable capable of accurately detecting a temperature rise in a multi-core cable laid in a case.

The present invention, for the purpose of solving the above problems, includes a twisted pair twisted pair of a pair of heat detection electric wires having a conductor and an insulator covering the periphery of the conductor, wherein the conductor is a nonmagnetic material and has tensile strength Provided is a heat detection wire made of a copper alloy having a value of 900 MPa or more.

Further, for the purpose of solving the above problems, the present invention includes the heat detection wire, a plurality of wires, and a sheath for collectively covering the heat detection wire and the plurality of wires, the melting point of the insulator of the heat detection wire This provides a multi-core cable lower than the melting point of the insulator of the plurality of wires.

Advantageous Effects of Invention According to the present invention, it is possible to provide a heat detection wire and a multi-core cable capable of accurately detecting a temperature rise in a multi-core cable laid in a case.

Fig. 1 (a) is a cross-sectional view showing a cross section perpendicular to the cable longitudinal direction of the multicore cable according to an embodiment of the present invention, and (b) is a cross-sectional view showing a cross section perpendicular to the cable longitudinal direction of the heat detection wire.
[Fig. 2] A perspective view showing the appearance of a multi-core cable.
[Figure 3] It is a cross-sectional view when the multi-core cable is accommodated in the groove of the case.
[Fig. 4] A photograph explaining the operation of the heat detection wire 2, (a) is a photograph before operation, (b) is a photograph after operation.
Fig. 5 is a cross-sectional view showing a cross section perpendicular to the cable longitudinal direction of a multicore cable according to a modification of the present invention.

[Embodiment]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 (a) is a cross-sectional view showing a cross section perpendicular to the cable longitudinal direction of a multicore cable according to the present embodiment, and Fig. 1 (b) is a cable longitudinal direction of a heat detection wire. It is a cross-sectional view showing a cross-section perpendicular to the Fig. 2 is a perspective view showing the appearance of a multicore cable. Fig. 3 is a cross-sectional view when the multi-core cable is accommodated in the groove of the case.

The inventors of the present invention conceived of incorporating a heat detection wire for detecting a temperature rise in a multicore cable disposed in a case in order to solve the problem as described above. In this case, in particular, the present invention was achieved by focusing on suppressing the reduction in the efficiency of non-contact electric power feeding by the heat detection wire and enabling the temperature rise in the multi-core cable to be accurately detected.

1 to 3, the multi-core cable 1 includes a heat detection wire 2, a plurality of wires 3, and a sheath covering the heat detection wire 2 and the plurality of wires 3 at once. ) (4) is provided.

This multi-core cable 1 is used to supply power by non-contact (for non-contact power supply), and is accommodated in the groove 11 of the case 10 and used. In this example, the case 10 includes a pair of sidewalls 12 arranged in parallel, and a bottom wall ( 13), and is formed in a U-shape which is rotated 90° clockwise when viewed in cross section as a whole. The groove 11 is a space surrounded by a pair of side walls 12 and a bottom wall 13, opened to the opposite side to the bottom wall 13 and having a rectangular shape when viewed in cross section.

(heat detection wire (2))

The heat detection wire 2 includes a twisted pair wire 22 twisted with a pair of heat detection wires 21, and a pressure-wound tape 23 wound around the twisted pair wire 22 in a spiral shape; , has a jacket 24 covering the periphery of the pressure winding tape 23 .

A pair of heat detection wires 21 constituting the twisted pair 22 includes a conductor (hereinafter referred to as a first conductor to distinguish it from a conductor of an electric wire 3 to be described later) 211; Insulators (hereinafter referred to as first insulators) 212 covering the periphery of the first conductors 211 (to be distinguished from the insulators of the electric wires 3 to be described later) 212 are provided, respectively. As the first conductor 211 , in a twisted state as the twisted pair 22 , it is preferable to use a thing capable of increasing the force of the first conductors 211 to approach each other toward the center of the twisted pair 22 .

As described above, the multi-core cable 1 is used for non-contact power feeding, and is wired over a long distance of, for example, 30 m or more in a factory or the like. Therefore, it is necessary to keep the electrical conductivity of the first conductors 211 high enough to detect a short circuit between the first conductors 211 even when they are wired over a long distance. In addition, strength is required so that disconnection does not occur even when wiring over a long distance. In the heat detection wire 2 according to the present embodiment, the outer diameter of the first conductor 211 is preferably set to 0.5 mm or more and 1.0 mm or less. By setting the outer diameter of the first conductors 211 to 0.5 mm or more, conductor resistance is suppressed and electrical conductivity is maintained high, and short circuits between the first conductors 211 can be detected even in long-distance wiring. In addition, by setting the outer diameter of the first conductors 211 to 0.5 mm or more, it is possible to suppress a decrease in the detection sensitivity due to a decrease in the force that the first conductors 211 try to approach each other, thereby improving the detection sensitivity of the temperature in the cable. can be improved On the other hand, by setting the outer diameter of the first conductor 211 to 1.0 mm or less, it is possible to suppress that the multi-core cable 1 becomes hard and difficult to bend, so that the multi-core cable 1 can be easily wired.

In the heat detection wire 2 according to the present embodiment, as the first conductor 211, a non-magnetic material made of a copper alloy having a tensile strength of 900 MPa or more is used. More specifically, as the first conductor 211, phosphor bronze containing 7 mass% or more and 9 mass% or less of tin and 0.03 mass% or more and 0.35 mass% or less of phosphorus is used. By using a non-magnetic material as the first conductor 211, loss in non-contact power feeding can be suppressed, and a decrease in efficiency of non-contact power feeding can be suppressed. In addition, by setting the tensile strength of the first conductor 211 to 900 MPa or more (preferably 930 MPa or more, more preferably 990 MPa or more), the first conductors 211 of the twin-stranded wire 22 are twisted with each other. (211) It is possible to increase the force to approach each other toward the center of the double stranded wire 22 . Accordingly, when the first insulator 212 is softened and melted, the first conductors 211 quickly move toward the center of the stranded wire 22 and the first conductors 211 come into contact with each other, and by the contact It becomes possible to improve the detection sensitivity of the temperature in a cable. In addition, from the viewpoint of improving the detection sensitivity by increasing the force between the first conductors 211 of the twisted pair 22 to approach each other to the center of the twisted pair 22, the elongation of the first conductor 211 is 10% It is preferable that it is less than (more preferably, less than 3%). In the present embodiment, a single-wire first conductor 211 made of phosphor bronze having a diameter of 0.9 mm and having a tensile strength of 998.9 MPa and an elongation of 2.4% was used. In addition, by setting the tensile strength of the first conductor 211 to 900 MPa or more, it is possible to secure the strength in which disconnection does not occur even when wiring over a long distance. The tensile strength and elongation of the first conductor 211 can be obtained by the tensile test method (test piece: No. 9B) conforming to JISZ2241 (2011).

Moreover, as a copper alloy used for the 1st conductor 211, it is not limited to phosphor bronze, For example, brass, beryllium copper, etc. can also be used. However, the first conductors 211 of the twisted pair 22 can increase the force to approach each other at the center of the twisted pair 22, and it is difficult to break the wire and use inexpensive phosphor bronze. It can be said that it is more preferable.

As the first insulator 212, an insulating resin having a relatively low melting point is used to melt when the temperature in the cable rises. More specifically, so that the first insulator 212 is melted (in other words, in other words, before the second insulator 32 (to be described later) of the electric wire 3 is melted by heat when the temperature in the cable is raised due to overcurrent or the like, Before the function of the electric wire 3 is lost due to the heat during the temperature rise described above, the first conductor 211 is short-circuited so that the temperature rise in the cable due to the occurrence of overcurrent is detected), the first insulator 212 The melting point of the electric wire 3 is lower than the melting point (for example, 105° C. or higher) of the second insulator 32 of the electric wire 3 . In the present embodiment, the melting point of the first insulator 212 is set higher than 80°C and less than 100°C (more preferably higher than 80°C, with the aim of operating at 100°C for several minutes (within 5 minutes) without operating at 80°C or lower. Preferably, it was set to about 90°C). Here, the first insulator 212 made of an ionomer resin having a melting point of about 89°C was used.

The thickness of the first insulator 212 is preferably 0.1 mm or more and 0.3 mm or less. By setting the thickness of the first insulator 212 to 0.1 mm or more, the mechanical strength of the first insulator 212 is secured, and unintentional damage to the first insulator 212 is suppressed to prevent malfunction of the thermal detection wire 2 . can be suppressed In addition, by setting the thickness of the first insulator 212 to 0.3 mm or less, when the first insulator 212 is softened and melted, the first conductors 211 are quickly brought into contact with each other, even though the temperature in the cable is rising. It is possible to suppress a defect in which the first conductors 211 do not contact each other. In this embodiment, the thickness of the first insulator 212 was 0.15 mm, and the outer diameter of the electric wire 21 for heat detection was 1.2 mm. The outer diameter of the twisted pair wire 22 twisted with the two heat detection wires 21 is 2.4 mm. Further, the first insulator 212 is a portion in which each of the pair of heat detection wires 21 constituting the twin stranded wire 22 is in contact with each other (the first insulator of the pair of heat detection wires 21 ) 212) The thickness of the portion in contact with each other is the same as the thickness of the portion where each of the pair of heat detection wires 21 do not contact each other (the first insulator 212 of the pair of heat detection wires 21) It is better to be thinner than the thickness of the non-contact part). Accordingly, when the first insulator 212 is softened and melted, the first conductors 211 are quickly brought into contact with each other, so that the first conductors 211 do not contact each other even though the temperature in the cable is rising. can be easily suppressed. At this time, it is preferable that the portions in which each of the pair of heat detection electric wires 21 constituting the twin stranded wire 22 contact each other are in surface contact. The thickness referred to herein is the shortest distance (minimum thickness) from the inner surface of the first insulator 212 to the outer surface of the first insulator 212 .

Fig. 4 is a photograph for explaining the operation of the heat detection wire 2, wherein (a) is a photograph before operation and (b) is a photograph after operation. 4(a) and 4(b), in the heat detection wire 2, the temperature inside the cable (the temperature around the wire 3) is the melting point of the first insulator 212 (89 in this embodiment). ℃) or higher and rises to a temperature lower than the melting point of the second insulator 32, and when the first insulator 212 is softened and melted by the heat at this time, the twisted first conductors 211 are interlinked with each other. The first conductors 211 move in the center direction of the stranded wire 22 by the force trying to approach each other to the center, and the first conductors 211 come into contact with each other, thereby electrically short-circuiting. At this time, the first insulator 212 is in a molten state, and the first insulator 212 existing between the first conductors 211 due to the force that the first conductors 211 try to approach each other. is pushed from the vicinity of the center of the stranded wire 22 . For this reason, the outer shape of the first insulator 212 does not have a circular shape, and the portion in contact with the first insulator 212 is slightly flattened. By detecting the short circuit of the two first conductors 211, the temperature rise in the multi-core cable 1 due to overcurrent or the like can be detected. In addition, in the photos of Figs. 4(a) and 4(b), in order to make it easier to check the cross-sectional shape of the heat detection wire 2, the heat detection wire 2 is filled with an epoxy resin, and cut After grinding the finished surface, the cut surface was photographed.

However, in the heat detection wire 2, the temperature around the heat detection wire 2 rises, so that the first insulator 212 softens before the two first conductors 211 are short-circuited, and the two first conductors 211 are As the distance between them approaches, the resistance value or capacitance between the two first conductors 211 changes. Therefore, by measuring the resistance value or capacitance between the two first conductors 211, it may be detected that the temperature around the heat detection line 2 is rising before the two first conductors 211 are short-circuited.

Although not shown in the drawings, the first insulator 212 may have a multilayer structure in which a plurality of layers made of an insulating resin composition are laminated. For example, when the first insulator 212 has a two-layer structure and the melting point of the inner layer is higher than the melting point of the outer layer, the temperature rise in the multi-core cable 1 can be detected step by step.

Further, when the first insulator 212 has a multi-layered structure, in at least one layer other than the layer closest to the first conductor 211, a particulate form having a higher melting point than the insulating resin constituting the first insulator 212 It may contain a substance. Since the first insulator 212 contains a particulate matter having a high melting point, when the temperature around the heat detection wire 2 rises, the particulate matter is press-fitted by the force that the first conductors 211 try to approach each other, so that the first Thinning of the insulator 212 is suppressed, making it possible to easily cause a short circuit between the first conductors 211 . If the particulate material is insulating, the particulate material is interposed between the first conductors 211 and there is a fear that a short circuit may not occur. Therefore, it is preferable to use a conductive material as the particulate material. As the particulate matter, for example, carbon particles can be used.

The twisting pitch of the twisted pair 22 may be about 20 times the outer diameter of the heat detection wire 21 (18 times or more and 22 times or less). Accordingly, it is possible to suppress the destruction of the first insulator 212 by the force while maintaining the force that the first conductors 211 try to approach each other. In addition, the twist pitch of the double stranded wire 22 is the space|interval of the longitudinal direction position where arbitrary heat detection electric wires 21 become the same circumferential direction in the longitudinal direction of the double stranded wire 22. As shown in FIG. Moreover, the outer diameter of the electric wire 21 for heat detection is 1.0 mm or more and 1.6 mm or less, for example.

As the pressure winding tape 23 wound around the double stranded wire 22, for example, a resin tape such as a polyester tape can be used. The pressure winding tape 23 is spirally wound around the twin strands 22 so that a part of the width direction overlaps each other.

The jacket 24 serves as a protective layer for protecting the stranded wire 22 . The melting point of the jacket 24 is preferably higher than the melting point of the first insulator 212 so that the jacket 24 does not melt before the first insulator 212 is melted. The jacket 24 is made of an insulating resin and is formed by hollow extrusion (so-called tube extrusion).

In addition, in this embodiment, the jacket 24 is made of an elastic body. In this embodiment, the heat detection wire 2 is arrange|positioned at the cable center of the multicore cable 1 . When the multi-core cable 1 is accommodated in the groove 11 , the multi-core cable 1 is accommodated in the groove 11 by pressing the multi-core cable 1 into the groove 11 of the case 10 . And when pressurizing the multicore cable 1, the electric wire 3 in the multicore cable 1 is pressed by the heat detection wire 2 arrange|positioned at the center of the cable. At this time, the jacket 24 of the heat detection wire 2 is elastically deformed by the force when the wire 3 is pressed, and the wire 3 in the sheath 4 is in the circumferential direction or diameter of the heat detection wire 2 . direction (in a cross section perpendicular to the cable length direction of the multicore cable 1, a direction along the circumference of the heat detection wire 2 or a direction along the outer diameter of the heat detection wire 2). Therefore, the outer shape of the multi-core cable 1 may be deformed according to the shape or size of the groove 11 . Accordingly, the multi-core cable 1 can be easily inserted into the groove 11 of the case 10 even if the outer diameter thereof is increased.

As described above, the jacket 24 of the heat detection wire 2 is elastically deformed to improve workability when the multi-core cable 1 is accommodated in the groove 11 . In addition, the shape of the jacket 24 is restored by easing the pressing force from the electric wire 3 after the multi-core cable 1 is accommodated in the groove 11 . By the restoring force of the jacket 24 at this time, the electric wire 3 in the sheath 4 acts to move to its original position (the position before being accommodated in the groove 11). Accordingly, the multi-core cable 1 accommodated in the groove 11 is restored to its shape before being deformed and is supported in the groove 11 . In this way, the jacket 24 of the heat detection wire 2 pushes the sheath 4 toward the case 10 (inner wall of the groove 11) through the electric wire 3, and the multi-core cable 1 is inserted into the groove 11. It also plays a supporting role.

All the electric wires 3 are in direct contact with the outer peripheral surface of the jacket 24 . That is, the outer peripheral surface of the heat detection wire 2 is in direct contact with all the electric wires 3 . As the jacket 24, it is sufficient to use a material having elasticity that changes shape due to external force. For example, a resin composition made of PVC (polyvinyl chloride) resin (heat-resistant vinyl resin) or urethane resin can be used. . In this embodiment, the outer diameter of the jacket 24 (that is, the outer diameter of the heat detection wire 2) was 3.1 mm. Also, in Fig. 1(a), in the cross section perpendicular to the longitudinal direction of the cable, all the electric wires 3 are in direct contact with the outer circumferential surface of the jacket 24 (the outer circumferential surface of the heat detection wire 2). not limited For example, in the multicore cable 1 in which an insert to be described later is not disposed between the heat detection wire 2 and the wire 3, at least one wire 3 is connected to the outer peripheral surface of the jacket 24 (heat detection wire ( It is good if the structure is in contact with the outer peripheral surface of 2). However, from the viewpoint of arranging the plurality of electric wires 3 in a balanced manner (at approximately equal intervals) around the heat detection wire 2, it is preferable that the outer peripheral surface of the heat detection wire 2 is in direct contact with all the electric wires 3 . good.

The jacket 24 consists of a single layer or multiple layers. In the case of multiple layers, for example, the jacket 24 consists of an inner layer and an outer layer. The inner layer is formed so that the inner surface may contact the double stranded wire 22 . The outer layer is formed so that the inner surface may contact the inner layer. The outer layer comes into contact with the electric wire 3 when the heat detection wire 2 is disposed in the multi-core cable 1 . That is, the outer peripheral surface of the outer layer becomes the outer peripheral surface of the jacket 24 . It is preferable that the thickness of an inner layer is thinner than the thickness of an outer layer. The thickness of the inner layer is, for example, 0.2 mm or more and 0.4 mm or less. The thickness of the outer layer is, for example, 0.2 mm or more and 0.4 mm or less. In this thickness range, it is preferable to make the thickness of the outer layer thicker than the thickness of the inner layer. Moreover, it is good that the total thickness of the jacket 24 in this case is 0.4 mm or more and 0.8 mm or less, for example. In the multi-core cable 1, the jacket 24 of the heat detection wire 2 has a laminated structure composed of the inner layer and the outer layer described above, so that the overall thickness of the jacket 24 is increased around the heat detection wire 2 A plurality of electric wires 3 can be easily adjusted to a thickness that makes it difficult to enter the center of the cable. If it becomes difficult for the plurality of electric wires 3 to enter the center of the cable, the plurality of electric wires 3 can be arranged around the heat detection wire 2 in a good balance (at approximately equal intervals). Thereby, it is effective in improving the precision of heat detection in the heat detection wire 2, and improving the efficiency of the non-contact electric power feeding of the wire 3. As shown in FIG.

In addition, the outer layer may be different from the inner layer in properties such as hardness and melting point. For example, even when both the inner layer and the outer layer are made of a resin composition containing a polyvinyl chloride resin as a main component, the outer layer and the inner layer each have different hardness. At this time, the hardness of the outer layer is preferably harder than that of the inner layer. Thereby, the outer layer can be easily peeled off from the inner layer. In addition, the hardness of the outer layer is preferably harder than that of the second insulator 32 constituting the electric wire 3 . Accordingly, it is possible to make it difficult to enter the plurality of wires 3 into the center of the cable.

Further, as shown in FIG. 5 , the heat detection wire 2 may have a reinforcing layer 25 on the outer periphery of the jacket 24 . The reinforcing layer 25 makes the cross-sectional shape of the heat detection wire 2 perpendicular to the cable length direction to be substantially circular, and the cross-sectional shape of the heat detection wire 2 when the heat detection wire 2 is placed in the center of the cable It plays a role in making it difficult to transform. By having such a reinforcing layer 25, it is possible to suppress the plurality of electric wires 3 from entering the center of the cable. Thereby, the plurality of electric wires 3 arranged around the heat detection wire 2 can be arranged at approximately equal intervals in the circumferential direction of the cable, and further from the heat detection wire 2 to the center of each of the plurality of wires 3 . can be approximately equal to the distance of In addition, when the heat detection wire 2 has a reinforcing layer 25 on the outer periphery of the jacket 24, the reinforcing layer 25 becomes the outer surface of the heat detection wire 2, and the electric wire 3 is in direct contact with the outer surface. do.

As the reinforcing layer 25, for example, a tape layer formed by winding a resin tape around the outer periphery of the jacket 24 in a spiral shape, an extruded resin layer formed by extruding an insulating resin by tube extrusion, or the like can be used. In the case where the reinforcing layer 25 is a tape layer, it may be multilayered. As the multilayer tape layer, for example, an inner tape layer formed by winding a resin tape spirally around the outer periphery of the jacket 24, and an outer tape layer formed by spirally winding a resin tape around the outer circumference of the inner tape layer. It is composed of a layered structure. It is preferable that the winding directions of each resin tape constituting the inner tape layer and the outer tape layer are different from each other. Accordingly, it is possible to easily express the role of the reinforcing layer 25 described above. It is preferable that the reinforcing layer 25 has a hardness harder than that of the second insulator 32 constituting the electric wire 3 . As the resin tape or insulating resin constituting the reinforcing layer 25, for example, polyethylene, fluororesin, or the like can be used.

(Wire (3))

The electric wire 3 has a second conductor 31 made of a twisted-pair conductor by collecting and twisting a plurality of strands, and a second insulator 32 covering the second conductor 31, respectively, have. As the six electric wires 3, those of the same structure are used. In the present embodiment, a tin-plated annealed copper wire was used as the wire used for the second conductor 31 . The outer diameter of the wire used for the second conductor 31 may be 0.15 mm or more and 0.32 mm or less. This is because, if the outer diameter of the wire is less than 0.15 mm, disconnection is likely to occur, and if it exceeds 0.32 mm, there is a risk that the second insulator 32 may be penetrated when the second insulator 32 is thinned.

As a method of twisting an element wire, a method called concentric twisting is known. However, when the second conductor 31 is formed by this method, the element wire is twisted in a stable state and the multi-core cable 1 is inserted into the groove 11 ), it becomes difficult to change the shape of the second conductor 31 due to an external force at the time of being accommodated in it. For this reason, so that the shape of the second conductor 31 is easily changed by an external force when the multi-core cable 1 is accommodated in the groove 11, a second conductor 31 formed by a twisting method is used. . In this embodiment, the second conductor 31 having an outer diameter of about 3.5 mm (3.0 mm or more and 4.0 mm or less) and a conductor cross-sectional area of 7 mm ² or more and 8 mm ² or less was formed by collecting and twisting 134 0.26 mm strands.

In order to increase the cross-sectional area of the conductor portion in the multi-core cable 1, the thickness of the second insulator 32 of each electric wire 3 is preferably as thin as possible. More specifically, the thickness of the second insulator 32 may be 1/2 or more and 1 or less times the outer diameter of the wire used for the second conductor 31 . When the thickness of the second insulator 32 is less than 1/2 of the outer diameter of the wire, the wire penetrates the second insulator 32 and There is a possibility that it may come out, and when it exceeds 1 time of the outer diameter of an elementary wire, the electric wire 3 will become a large diameter, and it will lead to the large diameter of the multicore cable 1 whole. In the present embodiment, the thickness of the second insulator 32 is about 0.2 mm (about 0.77 times the outer diameter of the element wire). In addition, from the viewpoint of making the thickness as thin as possible, the second insulator 32 of each electric wire 3 is preferably made of the same material and formed of a single layer.

In order to enable a larger power supply, the ratio of the outer diameter of the second conductor 31 to the outer diameter of the electric wire 3 may be 80% or more. In addition, if the second insulator 32 is too thin, as described above, defects such as the wire passing through the second insulator 32 occur. The ratio of the outer diameter may be 95% or less. In addition, in order to enable the supply of large-capacity power through non-contact, in the plurality of wires 3 , currents of the same magnitude may be supplied to each of the second conductors 31 .

As the second insulator 32, thin-wall molding is possible, and in order to facilitate elastic deformation of the jacket 24 of the heat detection wire 2, it is harder than the jacket 24 and strong against external pressure (multi-core cable 1). ) of a material that is not easily deformed by external force when accommodated in the groove 11), for example, ETFE (tetrafluoroethylene-ethylene copolymer), FEP (tetrafluoroethylene-hexafluoro propylene copolymer), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), etc., polyimide, and PEEK (polyether ether ketone) can be used. More preferably, as the second insulator 32, a fluororesin having good surface lubricity may be used. Accordingly, when an external force is applied, the electric wire 3 becomes easier to move within the sheath 4, so that the multi-core cable The insertion into the groove 11 of (1) becomes easier.

The second insulator 32 is formed by hollow extrusion (so-called tube extrusion). Accordingly, the second insulator 32 does not come into close contact with the wire, so that the wires can move with each other in the second insulator 32 , and the cross-sectional shape of the electric wire 3 is easily deformed when an external force is applied. Accordingly, insertion of the multi-core cable 1 into the groove 11 becomes easier.

(Assembly (6))

On the outer periphery of the heat detection wire 2, a plurality of electric wires 3 are twisted in a spiral shape. Hereinafter, what twists the some electric wire 3 around the heat detection wire 2 is called the assembly 6 .

When the number of wires 3 used in the assembly 6 is 1 to 3, the multi-core cable 1 is hardly deformed by an external force. Therefore, in the multi-core cable 1, the number of the electric wires 3 used for the assembly 6 is 4 or more. In this embodiment, the number of electric wires 3 used for the assembly 6 was made into six pieces which have the smallest outer diameter and can make the sum total of the conductor resistance of all electric wires 3 the lowest.

In the assembly 6, the electric wires 3 adjacent to each other in the circumferential direction of the cables are in contact with each other. Further, the electric wire 3 is in contact with the heat detection wire 2 . The outer diameter of the heat detection wire 2 is suitably adjusted to the outer diameter which can contact all the electric wires 3 when the six electric wires 3 are arrange|positioned without a gap in the circumferential direction of a cable. In this embodiment, the outer diameter of the heat detection wire 2 was made substantially equal to the outer diameter of the electric wire 3 .

It is preferable that the twisting direction of the assembly 6 is opposite to the twisting direction of the twisted pair 22 in the heat detection wire 2 . By making the twisting direction of the assembly 6 and the twisting direction of the double stranded wire 22 in the reverse direction, the twist of the electric wire 3 becomes difficult to untwist, and the heat detection wire 2 is held in a tightened state by the electric wire 3 thing becomes possible As a result, when the temperature in the cable rises, the first conductors 211 come into contact with each other easily by tightening the electric wires 3, and it becomes possible to improve the detection sensitivity. Moreover, the twist direction of the assembly 6 is the direction in which the electric wire 3 is rotating from the other end side to the one end side when the assembly 6 is seen from one end side. In addition, the twist direction of the twin strand 22 is the direction in which the electric wire 21 for heat detection is rotating from the other end side to one end side when the twin strand 22 is seen from one end side.

Moreover, in this embodiment, each electric wire 3 which comprises the assembly 6 is provided so that it may contact with the inner peripheral surface of the sheath 4, and the tape for pressure winding is not wound around the assembly 6 . This is because, when the tape is wound, the tape plays a role of regulating the movement of the electric wire 3 , and there is a fear that the workability at the time of inserting the multicore cable 1 into the groove 11 may decrease. Moreover, when it is necessary to keep the electric wire 3 in a twisted state in terms of production, a thread (such as a resin thread or cotton thread) is wound around the assembly 6 in a spiral shape. It is also good to close it.

A thread-like insert may be disposed between the heat detection wire 2 and the plurality of electric wires 3 and between the electric wire 3 and the sheath 4 . In order to suppress the burning of the insert due to the temperature rise in the cable, it is good to use one with high heat resistance (at least the heat resistance temperature is 100℃ or higher). By having an insert, the outer shape of the whole multicore cable 1 can be made close to a circular shape, and handleability can be improved. Moreover, in this embodiment, it is preferable that the thread-like insert is not arrange|positioned between the heat detection wire 2 and the some electric wire 3, and between the electric wire 3 and the sheath 4,. This suppresses the burning of the insert due to temperature rise, and furthermore, when an external force is applied to the multi-core cable 1, the electric wire 3 moves in the circumferential direction or the outer diameter direction of the heat detection wire 2 ( That is, to secure the air layer (5)).

(Sheath (4))

A sheath 4 is formed around the assembly 6 . In the multicore cable 1 according to the present embodiment, the sheath 4 is formed by hollow extrusion (so-called tube extrusion). The sheath 4 is formed in a hollow cylindrical shape having a hollow portion 41 along the longitudinal direction, and the heat detection wire 2 and the electric wire 3 (that is, the assembly 6)) is placed. Accordingly, in the multi-core cable 1 , the electric wires 3 can move with each other within the sheath 4 .

Moreover, as described above, in this embodiment, the tape for pressure winding is omitted, and each of the electric wires 3 has a structure in which it directly contacts the inner peripheral surface of the sheath 4 . It is preferable that the sheath 4 is formed so as not to strongly press the electric wire 3 in the radial inward direction as much as possible, and the contact area between the electric wire 3 and the sheath 4 is as small as possible (when viewed in cross section). and in point contact) is preferable.

The thickness of the sheath 4 is preferably 0.6 mm or more and 1.0 mm or less. If the thickness of the sheath 4 is less than 0.6 mm, the resistance to trauma or insulation performance is lowered, and if the thickness of the sheath 4 is greater than 1.0 mm, it leads to a large diameter of the multi-core cable 1 Because.

In addition, the sheath 4 is formed by blow extrusion and the thickness of the sheath 4 is made as thin as 1.0 mm or less, so that the sheath 4 is convex at the position of the electric wire 3 as shown in FIG. 2 . Concavities and convexities may be formed on the outer surface of the sheath 4 . Accordingly, when the multi-core cable 1 is inserted into the groove 11 of the case 10, it is easy to press the multi-core cable 1 into the groove 11 of the case 10, and the multi-core cable 1 and Since the contact area of the case 10 (the inner surface of the groove 11) can be made small, the insertion of the multicore cable 1 into the groove 11 becomes easier. In this embodiment, the sheath 4 made of polyvinyl chloride having a thickness of 0.8 mm was used.

(Evaluation test of heat detection wire (2))

As the first conductor 211, a single-wire phosphor bronze having a diameter of 0.9 mm, a tensile strength of 998.9 MPa, and an elongation of 2.4% (7 mass% to 9 mass% of tin, 0.03 mass% to 0.35 mass% of phosphorus, remainder) A heat detection wire 2 using false copper and trace amounts of unavoidable impurities) was tested and manufactured as an example, and its operation was evaluated. In the evaluation, the length of the heat detection wire 2 is set to 80 m, 100 m, and 400 m, and each heat detection wire 2 is put in a thermostat, and the time until the first conductors 211 are short-circuited. was measured. The temperature in the thermostat was 80° C., 100° C., 120° C., and 140° C., and each was tested.

In the same manner as in the embodiment, as the first conductor 211, phosphor bronze having a tensile strength of 891.0 MPa and an elongation of 2.3% (tin 5.5 mass% or more and 7 mass% or less, phosphorus 0.03 mass% or more and 0.35 mass% or less, the balance being copper and a trace amount of unavoidable impurities) were tested, and the heat detection wire of Comparative Example 1 having the same configuration as in Examples was tested and evaluated in the same manner as in Examples. In addition, as the first conductor 211, a 0.7% tin-containing copper alloy having a tensile strength of 676.7 MPa and an elongation of 1.9% (about 0.7 mass% of tin, the remainder being copper and trace amounts of unavoidable impurities) was used as in the embodiment. The heat detection wire of Comparative Example 2, which is a configuration, was tested and evaluated in the same manner as in Examples. Table 1 shows the first conductors 211 used in Examples and Comparative Examples 1 and 2.

The heat detection wire 2 of the Example and the heat detection wire of Comparative Examples 1 and 2 were evaluated. For the heat detection wires of Comparative Examples 1 and 2, the first conductors 211 were short-circuited at all lengths and at all temperatures. This did not occur, and the heat detection wire did not operate normally. On the other hand, Table 2 shows the measurement results of the heat detection wire 2 of the example.

As shown in Table 2, in the heat detection wire 2 of the example, in all lengths, it did not operate at 80°C for 2 hours, but operated at 100°C or higher for several minutes (approximately within 3 minutes), and good operation was obtained. could see what was going on.

(Actions and Effects of Embodiments)

As described above, in the heat detection wire 2 according to the present embodiment, the first conductor 211 is a non-magnetic material and is made of a copper alloy having a tensile strength of 900 MPa or more.

By configuring in this way, it is possible to suppress a decrease in efficiency when incorporated in the multi-core cable 1 for non-contact power feeding, and even when wiring over a long distance, defects such as disconnection can be suppressed, and conductor resistance can be suppressed. This makes it possible to accurately detect the temperature rise in the cable.

(Summary of embodiment)

Next, about the technical thought grasped|ascertained from the embodiment demonstrated above, the code|symbol etc. in embodiment are cited and described. However, each code|symbol in the following description does not limit the component in a claim to the member etc. which were specifically shown in embodiment.

[1] A conductor 211 and an insulator 212 covering the periphery of the conductor 211 and a pair of heat-sensing wires 21 twisted together, including a twisted pair 22, wherein the conductor 211 is , a heat detection wire (2) made of a copper alloy that is non-magnetic and has a tensile strength of 900 MPa or more.

[2] When the insulator 212 is softened or melted at a predetermined temperature, the pair of heat-sensing wires 21 is connected between the conductors 211 by the force that the conductors 211 try to approach each other. The heat detection wire (2) as described in [1], which moves toward the center of the double stranded wire (22) and contacts the conductors (211) with each other.

[3] As described in [2], the melting point of the insulator 212 is higher than 80°C and less than 100°C, the short circuit does not occur under an environment of 80°C, and the short circuit occurs within 5 minutes under an environment of 100°C A heat-sensing wire (2).

[4] The conductor 211 is described in any one of [1] to [3], wherein the conductor 211 is made of phosphor bronze containing 7 mass% or more and 9 mass% or less of tin and 0.03 mass% or more and 0.35 mass% or less of phosphorus, A heat-sensing wire (2).

[5] The heat detection wire (2) according to any one of [1] to [4], wherein the elongation of the conductor (211) is 10% or less.

[6] The double stranded wire 22 is surrounded by a jacket 24, the jacket 24 has an inner layer and an outer layer, and the thickness of the outer layer is thicker than the thickness of the inner layer [1] to [ 5], the heat detection wire (2) described in any one of.

[7] The double stranded wire 22 is surrounded by a jacket 24, and has a reinforcing layer 25 around the jacket 24, and the reinforcing layer 25 is The heat detection wire (2) according to any one of [1] to [6], which is a tape layer formed by spirally wound around a resin tape.

[8] The heat detection wire 2 described in any one of [1] to [7], the plurality of wires 3, and the heat detection wire 2 and the plurality of wires 3 are collectively covered A multi-core cable (1) having a sheath (4), wherein the melting point of the insulator (212) of the heat detection wire (2) is lower than the melting point of the insulator (32) of the plurality of wires (3).

[9] The multi-core cable (1) according to [8], wherein the plurality of electric wires (3) are twisted in a spiral shape around the heat detection wire (2).

Although the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all combinations of features described in the embodiments are essential for solving the problem. In addition, the present invention can be implemented with appropriate modifications without departing from the gist of the present invention.

1: Multi-core cable
2: heat detection line
21: heat detection wire
211: first conductor (conductor)
212: first insulator (insulator)
22: double stranded wire
23: pressure winding tape
24 : jacket
3: wire
31: second conductor
32: second insulator
4: sheath

Claims (9)

A conductor and a pair of wires for heat detection having an insulator covering the periphery of the conductor are twisted together,
The conductor is a non-magnetic material and is made of a copper alloy having a tensile strength of 900 MPa or more.
heat detection line.
According to claim 1,
In the pair of wires for heat detection, when the insulator softens or melts at a predetermined temperature, the conductors move toward the center of the stranded wire by the force that the conductors try to approach each other, and the conductors come into contact with each other heat detection line.
3. The method of claim 2,
The melting point of the insulator is higher than 80 ℃ and less than 100 ℃,
No short circuit under 80℃ environment,
If the short circuit occurs within 5 minutes under an environment of 100℃
heat detection line.
4. The method according to any one of claims 1 to 3,
The said conductor contains 7 mass% or more and 9 mass% or less of tin, and the heat detection wire which consists of phosphor bronze which contains 0.03 mass% or more and 0.35 mass% or less of phosphorus.
5. The method according to any one of claims 1 to 4,
A heat detection wire having an elongation of 10% or less of the conductor.
6. The method according to any one of claims 1 to 5,
The double stranded wire is surrounded by a jacket,
The jacket has an inner layer and an outer layer,
The thickness of the outer layer is thicker than the thickness of the inner layer
heat detection line.
7. The method according to any one of claims 1 to 6,
The double stranded wire is surrounded by a jacket,
having a reinforcing layer around the jacket;
The reinforcing layer is a tape layer formed by winding a resin tape around the jacket in a spiral shape.
heat detection line.
The heat detection wire of any one of claims 1 to 7,
a plurality of wires,
a sheath that collectively covers the heat detection wire and the plurality of wires
provided,
The melting point of the insulator of the heat detection wire is lower than the melting point of the insulator of the plurality of wires
Multicore cable.
9. The method of claim 8,
A multi-core cable in which the plurality of wires are twisted in a spiral shape around the heat detection wire.

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